“My relief is tempered by the knowledge that the Berlin audience were so inconvenienced.

“There was an amazing atmosphere in the house, it was going to be one of those unforgettable nights but not for this reason…

“We can’t wait to get back there on November 13th.”

The message was accompanied by a sketch and a picture of a handwritten note which said: “PS To the ones who sang Red Flag Day for me last night, thanks, those are some high notes in that one… as always, ‘you take us higher’.”

After the show ended on Saturday, band members Adam Clayton, Larry Mullen Jr and the Edge posted an apology on the website.

The statement said: “Bono was in great form and great voice prior to the show and we were all looking forward to the second night in Berlin, but after a few songs, he suffered a complete loss of voice.

“We don’t know what has happened and we’re taking medical advice.

“As always, we appreciate our audience’s understanding and all our fans’ support in Berlin and those who travelled from afar.”